Embodiments of the invention relate to a medical luminaire. More particularly, embodiments of the invention relate to a dental treatment luminaire for the intraoral illumination of a surgical field that has at least one illuminating unit with light-producing means and with optical means for generating a field of light in an object plane.
A luminaire conforming to this type is known from, for example, DE 10 2011 075 753 A1, pertaining to the applicant. In the case of the luminaire described therein, LEDs or LED arrays find application as light-producing means, to which various optical means are assigned, in order ultimately to ensure an illumination of the surgical field that is suitable for treatment purposes. These optical means comprise, for example, firstly a collimator for beam focusing and also a so-called condenser arranged downstream in the light path, with the aid of which the light beams are deflected and/or mixed in such a manner that the field of light being striven for is achieved in an object plane. As a rule, in addition to these optical means a cover plate has also been provided in the beam path, the function of which, however, consists primarily in protecting the optical and electronic components of the luminaire—that is to say, in particular, the light-producing means and also the optical units described above—against contamination and damage.
From the state of the art described above it is moreover already known to employ several illuminating units of such a type within a medical luminaire, which are arranged at varying angles and oriented in such a manner that the overall field of illumination results from the superposition of several individual illuminated fields, having the consequence that the formation of shadows, for example by the treating dentist, is minimised. Ideally, in this connection the illuminating units are oriented in such a manner and designed in such a manner that the individual fields of light are substantially identical—that is to say, they overlap completely.
The field of light ultimately generated should in this case be illuminated as homogeneously as possible, in order, also in the event of possible slight movements of the head of the patient, still to obtain a well-illuminated treatment field. In this way the situation can be avoided where, in the event of slight movements of the head of the patient, the dentist has to reposition the field of illumination each time by appropriate adjusting of the luminaire. The size of the treatment field to be illuminated in this case is limited by the specification of standard ISO968, which requires a maximal illuminance of 1200 lux at a spacing of 60 mm above the centre. The background for this regulation is that the patient is not to be dazzled unnecessarily.